Natural history of X-linked adrenoleukodystrophy in Japan

The natural history of X-linked adrenoleukodystrophy (ALD) was investigated, using a nation-wide retrospective study based on a questionnaire survey. The data on 145 patients, including 46 patients with the childhood cerebral form, 39 with adrenomyeloneuropathy (AMN), 33 with the adult cerebral form, 14 with the adolescent form and 13 with the olivo-ponto-cerebellar (OPC) form, were analyzed. Initial symptoms of the childhood cerebral form were intellectual (n=16) and visual (n=11) disturbances, whereas those of AMN were gait (n=37) and sensory (n=3) disturbances; the adult cerebral form, psychic (n=19) and gait (n=11) disturbances; the adolescent form, visual n=5) and gait (n=4) disturbances; and the OPC form, gait (n=9) disturbance. Patients with onset under the age of 8 years progressed more rapidly than those over 8 years old. Visual, hearing, gait and swallowing disturbances progressed more slowly in the older group. About half of AMN patients showed cerebral involvement about 10 years after onset. Patients with the OPC form also showed a similar progression. A Kaplan-Meier plot clarified the characteristic pattern of progression of neurological symptoms in each phenotype. These finding will improve the understanding of the natural history of X-linked ALD and will provide a basis for the evaluation of specific treatment for X-linked ALD.